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Frame Rating: GTX 660 vs HD 7870, plus HD 7790, HD 7850, GTX 650 Ti BOOST

Author: Ryan Shrout
Manufacturer: PC Perspective

Skyrim - GTX 660 vs HD 7870

The Elder Scrolls V: Skyrim (DirectX 9)


 

The Empire of Tamriel is on the edge. The High King of Skyrim has been murdered.

Alliances form as claims to the throne are made. In the midst of this conflict, a far more dangerous, ancient evil is awakened. Dragons, long lost to the passages of the Elder Scrolls, have returned to Tamriel.

The future of Skyrim, even the Empire itself, hangs in the balance as they wait for the prophesized Dragonborn to come; a hero born with the power of The Voice, and the only one who can stand amongst the dragons.

Our settings for Skyrim

Here is a video our testing run through, for your reference

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Unlike the first three games we looked at here, Skyrim at first blush appears to perform as you would expect: both SLI and CrossFire are scaling in our observed, Frame Rating based results. 

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The Skyrim engine definitely has more stutter and frame variance issues but nothing overly dramatic.  The green and black lines that represent the single cards are fairly thin and consistent but both CrossFire and SLI have more variance.  All four cards have some pretty bad spikes and "hitches" - as any Skyrim player will report is the case.

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Skyrim definitely has an interesting pattern to our FPS percentile graphs with much more gradual declining metrics.  Keep an eye on the CrossFire and SLI results and how they do come close to meeting the performance of the single cards towards the end; in fact CrossFire does drop below the HD 7870 single card around the 90th percentile.

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Despite those issues, none of the four tested combination really add a lot of variance or potential frame stutter.  Our scale on the left hand side doesn't breach the 5 ms mark.

 

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Welp, at 2560x1440, the HD 7870s in CrossFire start to see some issues where the FRAPS FPS and Observed FPS are not matching up!  The HD 7870 single card is faster than the GTX 660 but let's see what happened to CrossFire.

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There are some obvious issues where CrossFire again falls into the trap of the alternating high and low frame times that we saw in BF3, Crysis 3, etc.  This lends more credit to the idea that we theorized in the first article - the more GPU bottlenecked the game session is the more likely we are to see CrossFire problems exhibited. 

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Based on the minimum FPS data you can see that the HD 7870s in CrossFire quickly become only marginally faster than the single card while SLI stays above the single GTX 660 throughout. 

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Frame time variance of the CrossFire configuration looks bad once again with much higher variance than the other configurations, but even at the worst case we aren't going much above 10 ms.

 

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At 5760x1080, even without HD 7870 CrossFire results, we some interesting issues with SLI and scaling.  While the extra GTX 660 adds performance in some areas, the results are consistent.

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Interestingly, even though there are a lot of areas where performance looks to scale well and with tight frame times, there are a lot of spikes and hitches in the game that kind of make SLI a poorer solution that we would expect.  That being said, the CrossFire results dropped so many frames from our capture testing that we couldn't even get a result!

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The Radeon HD 7870 does perform better than the GTX 660 card from NVIDIA (41 FPS vs 33 FPS) but we do see solid scaling on the SLI configuration (53 FPS vs 33 FPS).  The hitching issues seen in the frame time plot show up here as the sudden drop in the minimum FPS right at the 95th percentile.

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You can see that not only does the GTX 660 SLI setup have the most frame time variance, it also goes up steeply after the 90th percentile and to some pretty high rates - reaching 40+ ms.

 

April 8, 2013 | 12:00 AM - Posted by Anonymous (not verified)

I just saw a video from valve discussing a tool called Telemetry from RAD games, it seems like it could be useful for analysis of game performance.

April 8, 2013 | 10:41 AM - Posted by Pendulously (not verified)

SUGGESTION FOR FRAME VARIANCE GRAPH:

You have already noted elsewhere that Percentile (1-99) is insufficient, for tracking large SPIKES in Frame Times, spikes which may occur only once every few seconds (i.e., once every few hundred frames, thus well beyond the 99th percentile threshold).

So you need a different dependent variable (x-axis), with 'milliseconds' remaining the independent variable (y-axis).

In a 10 minute gampeplay section (36000 Frames at 60 FPS), 36 Frames is equivalent to the 99.9th percentile (36000 divided by 1000).

If you put '36' on the x-axis (or perhaps multiples of 10), you could easily show people the effects of LARGE SPIKES IN FRAME TIMES. In many cases/circumstances, more illuminating than Frame Variance Graphs which show nothing beyond the 99th percentile.

April 8, 2013 | 11:52 AM - Posted by Stennan (not verified)

Are there any redeeming features to AMDs Crossfire solution?

April 8, 2013 | 02:06 PM - Posted by Anonymous (not verified)

Yes, they drop every other frame in crossfire and count it anyway and sell it to their fans as a superior frame rate than SLI.

AMS CF Frame numbers sold 80!(actual screen rate 40+stutter ! )

Wow it sure beats 76 from SLI !

Yes, a very "redeeming" quality.

April 10, 2013 | 09:12 AM - Posted by Stennan (not verified)

Thank you for not answering my question :)

I just wanted to know if there might be an upside with regards to perhaps input lag. Kind of hard to measure though.

April 11, 2013 | 04:17 PM - Posted by Anonymous (not verified)

Ok, here's a few thoughts. With the AMD runts and drops, and the fans now trying to claim "less input lag", my question is of course, "What are you aiming at?" !

With every other frame dropped or runted, you're getting ~50% of the game screen opponent positions from the frames displayed (first person shooter as an example of course since most games are that ) - so your opponents position on screen is "jumping" from one frame over to two frames ahead, changing position in a lurch - with that type of inaccuracy of on screen opponents, how is "less lag" going to help when one cannot see half the positions of the opposition, and aiming at those in between spots just is not directly occurring? you have no visual data for those positions, half the positions of your opponent !

You can see how that may present some real issues for the gamer, as far as firing accuracy.
Yes, one could develop a sort of compensation with practice, just like a similar amount of consistent input lag is gotten used to as the mind and muscles acclimate and compensate accordingly.

So, it appears to me missing frames and runts are anything but helpful, and the lag thenno lag, or the lag not running in sync with what appears on screen could be a real problem.

With equalized frame time outputs to screen, the "smoothness" factor certainly helps aiming at opponents and learning to time things correctly.

April 10, 2013 | 09:13 AM - Posted by Stennan (not verified)

Thank you for not answering my question :)

I just wanted to know if there might be an upside with regards to perhaps input lag. Kind of hard to measure though.

April 9, 2013 | 06:45 AM - Posted by fadeout (not verified)

Are we seeing that crossfire is inherently borked? Or are we seeing that the current drivers are not leveraging the potential of the hardware?

I'm thinking that drivers can be updated.

A note on the fanboy thingy, surely we need both companies to succeed to push one another to create ever faster and more powerful cards. No?

April 9, 2013 | 10:44 AM - Posted by bystander (not verified)

The problem has persisted at least two series of cards, but based on AMD's response, it likely has always existed. AMD had said they never considered frame metering. Instead, they had been focusing on delivering frames as fast as possible.

That to me would say the drivers were not borked per say, they just weren't trying to do anything about it. They weren't even aware of it.

Nvidia has their metering done with special hardware, but AMD believes they can do the same with software, which they probably can, though it may not be as ideal.

April 9, 2013 | 10:23 PM - Posted by Anonymous (not verified)

Not sure why the 660 is being compared to a 7870. MSRP is over $100 difference. 7850 makes more sense to me but there must be a good reason the 7870 was chosen.

April 9, 2013 | 10:57 PM - Posted by bystander (not verified)

The GTX 660 is the cheaper of the two cards. You must have the GTX 660ti in mind.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814130826
http://www.newegg.com/Product/Product.aspx?Item=N82E16814127699

April 13, 2013 | 03:32 PM - Posted by Anonymous (not verified)

The reason is a big fat smooch on the behind of amd and their fanboys.
Keep the raging natives a bit less restless.
You see, only 2 pages of comments, they didn't come in screaming bias while their radeon I don't believe any of this and "if it's true" it doesn't matter heads exploded.

They have all been made absolute idiots, as the years of their stupidity is apparent.

The years of them screeching no one can see over 30 fps anyway is exposed. It doesn't matter what they knew or did not know, they made every excuse and lie and fanboy promo they could over the course of years and now it is absolutely clear they were seeing only half the frames gobbled with screen wretching runts, but still claimed it was beauty incarnate.

They are fools, and we all know it.

April 11, 2013 | 03:15 PM - Posted by Arek (not verified)

It would be nice to see how a pair of gtx 580's fares, as I have these in my setup. Pretty please! *_*

April 13, 2013 | 07:21 PM - Posted by Johnny Rook (not verified)

I can't stress enough how amazing this is.

I have one or two questions though:

1. Is the ATI/AMD Dual-GPU cards like the HD7990 have the same "problems" has dual cards in SLi?

I have an HD5970 and I do recognize there are problems as far as stutter is concerned but, I notice, I have a clear visual "feeling" that something is not right in a very few games. Mostly those "heavy" titles like "Metro2033" and the new "Crysis 3".

2. Is the problem something related to the hardware itself, is it drivers or is it a mix of both?

April 13, 2013 | 07:31 PM - Posted by Johnny Rook (not verified)

Sorry, I meant "problems has dual cards in Crossfire?"

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